<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!--测试四个域输出相同key的值的顺序
EL表达式会分别是四个域中搜索数据输出,EL表达式在搜索的时候,是分别从小到大去搜索域对象
pageContext => request => Session => application
-->
<%

    pageContext.setAttribute("key", "pageContext");
    request.setAttribute("key", "request");
    session.setAttribute("key", "session");
    application.setAttribute("key", "application");

%>
<br>
${key} <br>

